I’ve just finished reading two adult books in which the title of the book you’re reading is the same as a book in the characters’ world. The Best of Youth by Michael Dahlie is about a ghostwriter of a YA novel called… The Best of Youth. Nick Hornby’s How to Be Good stars a protagonist whose husband is working on a book/lifestyle guide called How to Be Good — and his sanctimonious behavior is driving her crazy.
I can think of a few quick examples of this title-within-a-title in children’s lit: The Book of Lost Things by John Connolly, The Neverending Story by Michael Ende, and the upcoming Handbook for Dragon Slayers by Merrie Haskell. I’m sure there are many others. Can you think of some?